STAT3 and type 1 diabetes mellitus: Rheumatologists are also often part of multispecialty care teams that treat other autoimmune and autoinflammatory conditions that may initially present other specialists; for example, patients with STAT3 gain-of-function (GOF) syndrome with early onset type I diabetes (T1D), arthritis, and autoimmune cytopenias and lymphoproliferation may present to endocrinology, rheumatology, and/or hematology.